Complement component 3 as biomarker of disease activity and cardiometabolic risk factor in rheumatoid arthritis and spondyloarthritis

Objective

To analyze the relationship between complement component 3 (C3) and the prevalence of cardiometabolic risk factors and disease activity in the rheumatic diseases having the highest rates of cardiovascular morbidity and mortality: rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA).

Methods

This is a cross-sectional study including 200 RA, 80 PsA, 150 axSpA patients and 100 healthy donors. The prevalence of cardiometabolic risk factors [obesity, insulin resistance, type 2 diabetes mellitus, hyperlipidemia, apolipoprotein B/apolipoprotein A (apoB/apoA) and atherogenic risks and hypertension] was analyzed. Serum complement C3 levels, inflammatory markers and disease activity were evaluated. Cluster analysis was performed to identify different phenotypes. Receiver operating characteristic (ROC) curve analysis to assess the accuracy of complement C3 as biomarker of insulin resistance and disease activity was carried out.

Results

Levels of complement C3, significantly elevated in RA, axSpA and PsA patients, were associated with the prevalence of cardiometabolic risk factors. Hard clustering analysis identified two distinctive phenotypes of patients depending on the complement C3 levels and insulin sensitivity state. Patients from cluster 1, characterized by high levels of complement C3 displayed increased prevalence of cardiometabolic risk factors and high disease activity. ROC curve analysis showed that non-obesity related complement C3 levels allowed to identify insulin resistant patients.

Conclusions

Complement C3 is associated with the concomitant increased prevalence of cardiometabolic risk factors in rheumatoid arthritis and spondyloarthritis. Thus, complement C3 should be considered a useful marker of insulin resistance and disease activity in these rheumatic disorders.

Diagnostic potential of NETosis-derived products for disease activity, atherosclerosis and therapeutic effectiveness in Rheumatoid Arthritis patients

OBJECTIVES

1) To assess the association of NETosis and NETosis-derived products with the activity of the disease and the development of cardiovascular disease in RA; 2) To evaluate the involvement of NETosis on the effects of biologic therapies such as anti-TNF alpha (Infliximab) and anti-IL6R drugs (Tocilizumab).

METHODS

One hundred and six RA patients and 40 healthy donors were evaluated for the occurrence of NETosis. Carotid-intimae media thickness was analyzed as early atherosclerosis marker. Inflammatory and oxidative stress mediators were quantified in plasma and neutrophils. Two additional cohorts of 75 RA patients, treated either with Infliximab (n = 55) or Tocilizumab (n = 20) for six months, were evaluated.

RESULTS

NETosis was found increased in RA patients, beside myeloperoxidase and neutrophil elastase protein levels. Cell-free nucleosomes plasma levels were elevated, and strongly correlated with the activity of the disease and the positivity for autoantibodies, alongside inflammatory and oxidative profiles in plasma and neutrophils. Moreover, ROC analyses showed that cell-free nucleosomes levels could identify RA patients showing early atherosclerosis with high specificity. RA patients treated either with IFX or TCZ for six months exhibited decreased generation of NETs. Concomitantly, clinical parameters and serum markers of inflammation were found reduced. Mechanistic in vitro analyses showed that inhibition of NETs extrusion by either DNase, IFX or TCZ, further abridged the endothelial dysfunction and the activation of immune cells, thus influencing the global activity of the vascular system.

CONCLUSIONS

NETosis-derived products may have diagnostic potential for disease activity and atherosclerosis, as well as for the assessment of therapeutic effectiveness in RA.

Real-world cost-effectiveness of infliximab, etanercept and adalimumab in rheumatoid arthritis patients: results of the CREATE registry

Biological drugs have proven efficacy and effectiveness in treatment of rheumatoid arthritis (RA), although none has been shown to be superior. Few studies have evaluated the cost-effectiveness of biological drugs in real-life clinical conditions. The objective of this study was to compare the cost-effectiveness of infliximab, etanercept and adalimumab in achieving clinical remission (DAS28 < 2.6) when used as initial biological therapy. Patients were diagnosed with RA who began treatment with infliximab, etanercept or adalimumab in the Reina Sofia Hospital (Cordoba, Spain) between January 1, 2007, and December 31, 2012. Effectiveness was measured as the percentage of patients who achieved clinical remission after 2 years. The cost analysis considered the use of direct health resources (perspective of the healthcare system). Cost-effectiveness was calculated by dividing the total mean cost of each treatment by the percentage of patients who achieved remission. One hundred and thirty patients were included: 55 with infliximab, 44 with adalimumab and 31 with etanercept. After 2 years, 45.2 % of patients with adalimumab achieved clinical remission, versus 29.1 % with infliximab (p = 0.133) and 22.7 % with etanercept (p = 0.040), with no differences between etanercept and infliximab (p = 0.475). The average total cost at 2 years was €29,858, €25,329 and €23,309 for adalimumab, infliximab and etanercept, respectively, while the mean cost (95 %CI) to achieve remission was €66,057 (48,038–84,076), €87,040 (78,496–95,584) and €102,683 (94,559–110,807), respectively. Adalimumab was more efficient than etanercept (p < 0.001) and infliximab (p = 0.026), with no differences between etanercept and infliximab (p = 0.086). Adalimumab was the most cost-effective treatment in achieving clinical remission in real-life clinical conditions in RA patients during the study period.

Cost-effectiveness of clinical remission by treat to target strategy in established rheumatoid arthritis: results of the CREATE registry

To analyse the cost-effectiveness, in daily clinical practice, of the strategy of treating to the target of clinical remission (CR) in patients with established rheumatoid arthritis (RA), after 2 years of treatment with biological therapy. Adult patients with established RA were treated with biological therapy and followed up for 2 years by a multidisciplinary team responsible for their clinical management. Treatment effectiveness was evaluated by the DAS28 score. The direct costs incurred during this period were quantified from the perspective of the healthcare system. We calculated the cost-effectiveness of obtaining a DAS28 < 2.6, considered as CR. The study included 144 RA patients treated with biological therapies. After 2 years of treatment, 32.6% of patients achieved CR. The mean cost of achieving CR at 2 years was 79,681 ± 38,880 euros. The strategy of treatment to the target of CR is considered the most effective, but in actual clinical practice in patients with established RA, it has a high cost.

Inter-rater reliability of clinical mobility measures in ankylosing spondylitis

BACKGROUND

Several measurements are often used in daily clinical practice in the assessment of Ankylosing Spondylitis (AS) patients. The Assessment in SpondyloArthiritis International Society (ASAS) recommend in its core set: chest expansion modified Schöber test, Occiput to wall distance, lateral lumbar flexion, cervical rotation and The Bath Ankylosing Spondylitis Metrology Index (BASMI). BASMI also includes five measurements, some of them recommended by ASAS. Three versions of BASMI have been published with different scales and intervals for each component of the index. Though studies about reliability of these measurements are needed. The aim of this study was to analyze inter-rater reliability of recommended spinal mobility measures in AS.

METHODS

We examined reproducibility of spinal mobility measurements on 33 AS patients performed by two experienced rheumatologists in the same day. Descriptive statistics, Intraclass Correlation Coefficients (ICC), and Smallest Detectable Difference (SDD) using the Bland-Altman criteria were obtained for all the measurements.

RESULTS

Chest expansion showed the lowest value of ICC (0.66) and occiput-wall the highest (0.97). SDD was 2.43 units for BASMI2 and 1.27 units for BASMI10.

CONCLUSIONS

Reliability according to ICC was moderate to high in all measurements. BASMI10, instead BASMI2, must be used: measurements used to calculate are the same but there is better reliability. Inter-rater variation, expressed as SDD, must be taken in account: smaller improvements do not demonstrate the efficacy of treatment because they can be due to experimental error and not to the treatment itself.